1. Fields of the Invention
This invention relates to freight containers. It particularly relates to the type of freight container called a platform based container or flatrack.
Freight containers have long been standardised so as to facilitate international trade. This means that the associated handling and transport devices have also been standardised. In particular, the exact location and spacing of the stacking points and lifting points of the containers have been standardised and so cranes, stacking trucks, vehicles and so on have been built to accept the container having such standardised fitments.
Recently, a move has been made towards using longer, taller and wider containers, particularly on inland routes, to optimise cargo carrying efficiency.
For a rigid freight container, all that is necessary is to provide the lifting and fixing points at the standard positions, extending the container structure outside the standard dimensions as required. However this cannot be done readily with platform based containers known as flatracks.
2. Description of the Prior Art
Flatracks comprise a platform on which a load is carried and a pair of end walls which, during transit of freight, are locked in an upright condition so as to define the freight carrying space together with the platform. When the freight has been unloaded, the end walls are stowed relative to the platform so that a number of flatracks can be stacked and returned empty. Since the structure is intrinsically lighter than a rigid walled container and since it can be folded into a compact space, substantial economies can be achieved in the use of flatracks compared with rigid containers.
However, the move towards making containers longer has not hitherto been successful in connection with flatracks because the lifting and stacking formations are provided on the end walls. While it would be desirable to extend the platform and to provide lifting and stacking formations inboard of the end walls, no satisfactory means has hitherto been suggested for doing this, bearing in mind that any upright structures on the flatrack need to be fully stowable with respect to the platform.